//private async void VisibilyatorAsync(bool flag)
        //{

        //    double opacityListView;
        //    double opacityIndicator;
        //    if (flag)
        //    {
        //        opacityIndicator = 1;// true = loading
        //        opacityListView = 0;
        //    }
        //    else
        //    {
        //        opacityIndicator = 0;
        //        opacityListView = 1;
        //    }

        //    await ItemIndicator.FadeTo(opacityIndicator, App.AnimationSpeed, Easing.SinIn);
        //    await ItemsListView.FadeTo(opacityListView, App.AnimationSpeed, Easing.SinIn);
        //    this.ItemIndicator.IsEnabled = flag; this.ItemIndicator.IsVisible = flag; this.ItemIndicator.IsRunning = flag; this.ItemsListView.IsVisible = !flag;
        //}

        private async void VisibilyatorAsync(bool flag, int mode)
        {
            if (mode == 0)
            {
                double opacityListView;
                double opacityIndicator;
                if (flag)
                {
                    opacityIndicator = 1;// true = loading
                    opacityListView  = 0;
                }
                else
                {
                    opacityIndicator = 0;
                    opacityListView  = 1;
                }

                await ItemIndicator.FadeTo(opacityIndicator, App.AnimationSpeed, Easing.SinIn);

                await ItemsListView.FadeTo(opacityListView, App.AnimationSpeed, Easing.SinIn);

                this.ItemIndicator.IsEnabled = flag; this.ItemIndicator.IsVisible = flag; this.ItemIndicator.IsRunning = flag; this.ItemsListView.IsVisible = !flag;
            }

            if (mode == 1)
            {
                double opacityIndicator;
                if (flag)
                {
                    opacityIndicator = 1;// true = loading
                }
                else
                {
                    opacityIndicator = 0;
                }

                await ItemIndicator.FadeTo(opacityIndicator, App.AnimationSpeed, Easing.SinIn);

                this.ItemIndicator.IsEnabled = flag; this.ItemIndicator.IsVisible = flag; this.ItemIndicator.IsRunning = flag;
            }
        }